<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
        div p:first-of-type{
            color: red;
        }
    </style>

</head>
<body>

<div>
    <p>dsfsdgfdsgdfg</p>
    <p>dsfsdgfdsgdfg</p>
    <p>dsfsdgfdsgdfg</p>
</div>

</body>
</html>